Setting a new precedent? Are you serious? As opposed to putting this country into a conflict, where the President has absolute powers to do that?
Given that there have been numerous legal challenges to the emergency power rules, these rules are following the laws as they were intended. If the governors had no power, and this pandemic was left to its own demise, the odds of ADDING these emergency powers in most states would be pretty darned high. Just like they are to declare a disaster area. All of these emergency powers are temporary, and to keep them going requires some action by the legislature. Sadly, because this has turned into a political argument vs. science, it's easy for the Racist party to do nothing, and then just get upset when they are called out on it, and the governors are forced to extend the emergency actions.
The system is supposed to be a multi-stream system- where the governors powers are limited, and the legislature is supposed to follow up on their actions. But that actually requires the legislature to actually do *something*. When dumpy gets out of power, and people actually realize how dangerous this is, *maybe* they will start acting, and passing temporary laws that back up governor's actions. I doubt that, though. The Racist party has played this down so much that they can certainly be called murders. Especially when you see other countries around the world who has dealt with this MUCH better than we have with MUCH less resources.
As I see this current situation, Biden does not have the same power as he does with the military, to make an absolute mandate. That's up to the governors. What Biden CAN do is change the tone, and make sure that the government is set up to support people, in general, as opposed to just the rich- repeal the dump tax cuts, and use that money to support real people out of work. Working with congress, of course, since he also does not have the absolute ability to do that.